Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: A chainsaw starting apparatus comprises a frame, a first crank arm, a second crank arm, and a locking mechanism. The frame is designed to occupy a fixed position relative to a floor surface. The first crank arm and the second crank arm are each rotationally supported by the frame and interconnected to produce rotational movement of one arm upon rotational movement of the other arm. The locking mechanism may be used for releasably attaching a chainsaw to the frame.

Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: Apparatus and method for mixing a fluid dispersion disposed in a container having either a cylindrical or a square shape. The apparatus includes a holding structure having a retaining structure connected to a base. The retaining structure prevents lateral movement of the container both when the container has a cylindrical shape and when the container has a generally square shape with a width substantially equal to the diameter of the cylindrical shape. The apparatus rotates the container about at least one axis.

Abstract: The disk drive array data storage subsystem maps between virtual and physical data storage devices and schedules the writing of data to these devices. The data storage subsystem functions as a conventional large form factor disk drive memory, using an array of redundancy groups, each containing N+M disk drives. This system copies data records by simply creating a duplicate data record pointer in a virtual track directory to reference the original data record. This enables the host processor to access the data record via two virtual addresses while only a single physical copy of the data record resides in the data storage subsystem.

Abstract: The present invention comprises a method for enhancing data integrity during write operations in a data storage subsystem which comprises an array of redundant, interconnected disk drives. A data storage subsystem is disclosed which provides for writing data segments spread across N disk drives of the array and provides for generating and recording redundancy information spread across M disk drives. Redundancy information is used for reconstructing erroneous data in the case of a disk drive failure. It may be desirable to write a final portion of the data last, after other portions of the data and associated redundancy information have been recorded to the disk drives. The last portion of the data segments may contain information that validates the data. It is common to automatically generate the redundancy information as the data is written to the disk drives. The generated redundancy information is then later written to the disk drives.

Abstract: The data record copy apparatus for a virtual memory system instantaneously makes a copy of a selected data record by simply generating a new set of pointers to reference the same physical memory location as the original reference pointer. All the pointers referencing the same physical memory space are stored in the virtual memory mapping tables to record all the virtual addresses of the data record. When the original data record is staged to an associated cache memory or a copy of the data record is in cache memory, the consistency of the data record is maintained by loading all the virtual addresses of the data record from the mapping tables to the hash table and collision list of the cache memory. Thus, any access of one of these virtual addresses will result in the virtual memory system locating the single data record instance in cache memory.

Abstract: The use of a dynamically mapped virtual memory system permits the storage of data so that each data record occupies only the physical space required for the data. Furthermore, the data storage subsystem manages the allocation of physical space on the disk drives and does not rely on the file extent defined in the count key data format. Data compaction apparatus is provided to remove the gaps contained in the stream of count key data records received from the host processor. A data compression algorithm is then used to compress the received data into a compressed format for storage on the disk drives. It is the compacted, compressed data that is finally stored on the disk drives. Furthermore, any data record received from the host processor absent data in the user data field therein is simply listed in the virtual memory map as a null field occupying no physical space on the disk drives.

Abstract: A tubewave damper probe for the suppression of borehole tubewaves in seismic applications is disclosed. The damper probe is suspended into a borehole by means of a cable and is comprised of a housing, a gas-filled bladder within the housing, and a plurality of valves located on the housing. The damper probe operation is based on a modified Helmholtz resonator effect. The bladder is precharged before insertion into the borehole, and pressure variations within the borehole cause the bladder to expand or contract. The valves are designed such that expansion of the bladder causes the valves to close, and contraction of the bladder causes the valves to open. The valves also prevent over-expansion of the bladder.

Abstract: The early start mode data transfer apparatus coordinates the reading and writing of data files into and out of the data buffer of the tape control unit so that a data file can be written into the data buffer while another data file is concurrently being read out of the data buffer. Thus, both the host computer and the associated tape drive units can be active at the same time reading or writing data files into the data buffer of the tape control unit. The early start mode data transfer apparatus closely coordinates the reading and writing activity of the host computers and the associated tape drive units to avoid the overwriting data files in the data buffer as well as emptying the data buffer before the complete data file is written therein.

Abstract: The moving data storage media mode/direction change optimization apparatus makes use of information received concerning the mode and direction of the next operation to be performed by the data storage system to efficiently reposition the media in a single repositioning operation. In the case where the data storage media is a magnetic tape, the tape control unit receives information concerning the mode and direction of the next operation to be performed prior to the completion of the tape transport automatic repositioning cycle. The tape control unit signals the tape transport to abort the standard repositioning operation and instead to initiate a new repositioning operation which repositions the magnetic tape based on the mode and direction of both the presently executing operation and the next operation.

Abstract: The improved data compression system concurrently processes both strings of repeated characters and textual substitution of input character strings. In this system, the performance of data compression techniques based on textual substitution are improved by the use of a compact representation for identifying instances in which a character in the input data stream is repeated. This is accomplished by nesting a run length encoding system in the textual substitution system. This structure adds the recognition of runs of a repeated character before the processor performs the textual substituted data compression operation. A further performance improvement is obtained by expanding the alphabet of symbols stored in the compressor's dictionary to include both the characters of the input data stream and repeat counts which indicate the repetition of a character.

Abstract: Seismic cable shielding method and apparatus. Shielding is obtained by switching unused wire pairs to ground via a roll-along switch which is connected to system ground. Grounding of the unused conductors in the cable is accomplished by ground connections at the roll-along switch. By grounding the unused conductor pairs (all pairs except those required for the sensor signals) within the cable, partial shielding is provided between the active wire pairs and cross-talk is reduced to a negligible level. Additional wire pairs are hardwired to system ground and distributed uniformly throughout the cable cross section to form an interstitial shield.

Abstract: The adaptive data compression apparatus is located within a tape drive control unit which is interposed between one or more host computers and one or more tape transports. The adaptive data compression apparatus functions to efficiently compress a user data file received from a host computer into a bit oriented compressed format for storage on the magnetic tape that is loaded in the tape transport. The data compression apparatus divides each block of an incoming user data file into predetermined sized segments, each of which is compressed independently without reference to any other segment in the user data file. The data compression apparatus concurrently uses a plurality of data compression algorithms to adapt the data compression operation to the particular data stored in the user data file. A cyclic redundancy check circuit is used to compute a predetermined length CRC code from all of the incoming user data bytes before they are compressed.

Abstract: For a downhole seismic tool, a securing mechanism which uses an arm which swings from the side of tool and into contact with the earth, causing the tool also to come to rest against the opposite side of the borehole on at least one pair of lugs protruding from the opposite side of the tool.

Abstract: A temperature recorder suitable for circulation with a well drilling fluid is provided with a spherical casing and/or a plurality of minute samples of known melting point and/or positioning of the samples in the mouth of a capillary structure so that the melting of the sample is unambiguous.

Abstract: Disclosed is an apparatus for transducing seismic signals and a method for placing said apparatus for detecting seismic signals. The apparatus comprises at least one geophone preferably embedded in a polymeric material contained in a tubular member. A lower portion of the tubular member preferably contains ballast. The tubular member is preferably cemented into a borehole.